Rehab begins Wednesday on Wissahickon's Walnut Lane Bridge

What was once the world’s largest concrete bridge - just over 100 years ago - is set to see some rehab work starting Wednesday, PennDOT announced Monday.

The $14.7 million rehabilitation project of the 107-year-old bridge spanning the Wissahickon Creek will last until August 2017. For now the bridge will remain open during construction, but the lanes will be narrowed and traffic, slowed. Starting next spring, the bridge will be closed to vehicular traffic for about six months.

The project will include the replacement of bridge deck with a new concrete deck, the replacement of existing sidewalk, sidewalk supports and balustrades, and repair to support abutments and piers with concrete designed to match the architectural line and texture of the existing bridge.

A cracked plaque on the northeast corner will also be replaced, and new tear-drop street lights will be installed along the bridge. A temporary structure under the bridge, protecting Forbidden Drive, will be removed.

The contractor, Buckley and Company, Inc. of Philadelphia, will also rebuild the existing roundabout on Walnut Lane in Germantown with new landscaping, sidewalks, and curb ramps. Construction costs are being covered entirely with federal funds.

Bridge rehab work was originally slated to begin in 2013, but the issues with the contractor awarded the original bid led PennDOT to drop that contractor and re-advertise the bid.